Freshman Rep. Adam Kinzinger (R) defeated twenty year veteran Rep. Don Manzullo (R) in a primary battle that provided for some clear contrast in age and experience between the two incumbents by a 56% to 44% margin. Kinzinger is widely viewed as a young rising star in congress and the temperature of the race was turned up in recent days as various members in the Republican House leadership contributed to both candidates and raised the eyebrows of many in the GOP caucus. His strong performance in this primary will only strengthen his solid reputation on the campaign trail. Following redistricting, the new IL-16 contained 44.1% of Manzullo’s old IL-16 compared to 30.9% of Kinzinger’s old IL-11 district. Predictably, the old part of each incumbent’s district went strongly for the familiar candidate, but in the 25% of the district that neither candidate ran in back in 2010, Kinzinger was able to win a commanding percentage to overcome Manzullo’s advantage of a larger starting base of familiar voters. Kinzinger is currently unopposed to win re-election in the general election. In another high profile primary battle in Illinois, Rep. Jesse Jackson, Jr. (D) faced a challenge that never materialized as competitive from former Rep. Debbie Halvorson (D). Jackson won handily by a 71% to 29% margin in IL-2. Halvorson was defeated after serving just one term in 2010 by Kinzinger. The IL-10 Democrat primary battle to face GOP incumbent Bob Dold also received considerable attention. Many organizations with more liberal leanings were backing Ilya Sheyman, who was unsuccessful against the candidate who was a better match to other Democrats in the district, Brad Schneider. With Democrats firmly in control of the redistricting process in Illinois, several GOP freshmen will face much tougher battles in November. The likely gains made simply through redrawing lines will provide Democrats with more gains here than any other state. Reps. Walsh (IL-8), Dold (IL-10) and Schilling (IL17) all are sitting in new districts that President Obama won with at least 60% of the vote in 2008 while Reps. Kinzinger and Hultgren are in districts that Obama won. Incumbents Bobby Rush (D-IL1), Dan Lipinski (D-IL3), Danny Davis (D-IL7), Jan Schakowsky (D-IL9), and Tim Johnson (R-IL13) all received more than two-thirds of the votes in their contested primaries. Through the four states that have held congressional primaries, incumbents running against challenger candidates (and not other incumbents) have now won 41 of 42 contests (97.6%). Despite this high early re-election rate, the next Senate and House will have another large freshman class as a result of open seats created by retirements, redistricting and other factors. There will be at least 53 freshmen in the House and at least 10 more in the Senate when January rolls around. Here’s an early look at how the next freshman class compares to past elections:

With candidate filing not yet closed in several states and 46 states still to hold their primaries, the 2012 election is guaranteed to produce a larger class than the last redistricting cycle of 2002. 2012 congressional incumbent vs. incumbent matchups: Democrat incumbents facing each other in the PRIMARY (7):